Hygienic absorbent articles such as for example sanitary napkins and pantyliners are often formed by a liquid permeable topsheet, a liquid impermeable backsheet and an absorbent core positioned between the topsheet and the backsheet. The backsheet is usually provided with an area comprising a pressure sensitive adhesive (PSA) for securing the disposable absorbent articles to the users' undergarments.
In particular, the use of hot melt and emulsion-based adhesives is general technical standard. The application of emulsion-based adhesives onto the backsheets of absorbent articles for garment fastening is for instance known from SE-A-374,489. The use of hot melt adhesives for this purpose is for instance described in EP-A-140,135 or in WO 00/61054.
The user of these articles normally releases the adhesive (by unwrapping the article from its package and/or removing an adhesive release sheet) and applies the article on the panties in its correct position. PSA can be provided at various adhesive strength, but normally a PSA which has a weak adhesion on the panties is used so to ensure that panties are not damaged upon removal of the article, as well as to avoid that adhesive residues are left. This has the side effect that absorbent articles may not stay perfectly in place during use, especially if the person wearing them is moving a lot e.g. by having a sport session. In some cases absorbent articles may shift from their intended position thus reducing their protective effect and possibly causing staining on panties or underwear. In order to limit this problem it has been proposed to combine mechanical fasteners with conventional PSA.
Mechanical fasteners for this application have been described e.g. in U.S. Pat. No. 4,959,265 by 3M which describes a pressure-sensitive adhesive tape fastener, the backing of which has an array of bluntly pointed stems protruding beyond the pressure-sensitive adhesive. The stems are able to penetrate woven fabrics or other foraminous substrates thus offering a higher resistance to shifting than conventional PSA.
However the fastener described in U.S. Pat. No. 4,959,265 still is not completely satisfactory in terms of grip and of safety on the garment. In fact the stems are quite short and the rugosity of their surface is not controlled.
Therefore there is a need for improved absorbent articles which incorporate an improved fastening mean which provide better stay in place and better safety on garments.